Exchange ActiveSync and Outlook.com calendar issues

Several issues syncing / editing / creating calendar items on phone:

1. Changes made to the reminder time are not saved.

2. Edits made to existing appointments are unable to be synced - get 'Sync protocol error'

3. New appointments created also will not sync.

phone - HTC Sensation running Android 4.0.3 and Exchange ActiveSync.

Mail and Contacts sync just fine.

The calendar is basically 'read only' as any edits made on the phone results in sync errors.

Before updating to Outlook 2013 and EAS on the home PC, I constantly received sync errors in outlook 2010 with the Hotmail connector.

Question about Outlook Express